I encountered a small panel in a house the other day that was full. There was the possibility that a 240 circuit would need to be added. Could I just as easily added a subpanel, skirting the option of changing out the panel altogether?

It's been a little while, so forgive me if my memory is rusty. Correct me if I'm wrong. First, one 240 circuit breaker has to be replaced with a 60 amp for the sub-feed. The sub is fed with #6 hots and neutral and a # 8 ground. Right?

You are in referance to copper? also keeping the grounds all tied to grnd bar, tied to panel box, and keeping all neutrals together on a floating bar, seperate from grounds? Yah that sounds like your memory is working great...